Gateway DNS

Overview

Cloudflare is a global network designed to make everything you connect to the Internet secure, private, fast, and reliable.

In this documentation, you will learn how to collect and send Cloudflare Gateway DNS logs to SEKOIA.IO.

Benefit from SEKOIA.IO built-in rules and upgrade Cloudflare Gateway DNS with the following detection capabilities out-of-the-box.

SEKOIA.IO x Cloudflare Gateway DNS on ATT&CK Navigator

SEKOIA.IO Intelligence Feed

Detect threats based on indicators of compromise (IOCs) collected by SEKOIA's Threat and Detection Research team.

Effort: elementary

Sliver DNS Beaconing

Detects suspicious DNS queries known from Sliver beaconing

Effort: intermediate

Event Categories

The following table lists the data source offered by this integration.

Data Source	Description
`DNS records`	DNS Gateway logs

In details, the following table denotes the type of events produced by this integration.

Name	Values
Kind	`event`
Category	`network`
Type	`info`

Event Samples

Find below few samples of events and how they are normalized by SEKOIA.IO.

test_dns.jsontest_dns_device.json

{
    "message": "{\"ApplicationID\":0,\"ColoCode\":\"CDG\",\"ColoID\":533,\"Datetime\":\"2023-02-24T12:12:07Z\",\"DeviceID\":\"\",\"DeviceName\":\"\",\"DstIP\":\"172.12.12.1\",\"DstPort\":23,\"Email\":\"\",\"Location\":\"AWS VM\",\"LocationID\":\"a26c188f-10c2-4333-8ed4-c823fafa06f6\",\"MatchedCategoryIDs\":[],\"MatchedCategoryNames\":[],\"Policy\":\"\",\"PolicyID\":\"\",\"Protocol\":\"udp\",\"QueryCategoryIDs\":[],\"QueryCategoryNames\":[],\"QueryName\":\"ip-111-30-40-252.eu-west-3.compute.internal\",\"QueryNameReversed\":\"internal.compute.eu-west-3.ip-111-30-40-252\",\"QuerySize\":72,\"QueryType\":1,\"QueryTypeName\":\"A\",\"RCode\":3,\"RData\":[],\"ResolvedIPs\":[\"104.18.4.35\",\"104.18.5.35\"],\"ResolverDecision\":\"allowedOnNoPolicyMatch\",\"SrcIP\":\"12.122.186.81\",\"SrcPort\":42424,\"TimeZone\":\"\",\"TimeZoneInferredMethod\":\"noScheduleConfigured\",\"UserID\":\"\"}",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "gateway_dns",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "destination": {
        "ip": "172.12.12.1",
        "port": 23,
        "address": "172.12.12.1"
    },
    "@timestamp": "2023-02-24T12:12:07Z",
    "dns": {
        "question": {
            "name": "ip-111-30-40-252.eu-west-3.compute.internal",
            "type": "A",
            "subdomain": "ip-111-30-40-252.eu-west-3.compute"
        },
        "resolved_ip": [
            "104.18.4.35",
            "104.18.5.35"
        ],
        "response_code": "NXDomain"
    },
    "network": {
        "protocol": "dns",
        "transport": "udp"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "source": {
        "port": 42424,
        "ip": "12.122.186.81",
        "address": "12.122.186.81"
    },
    "cloudflare": {
        "ApplicationID": 0,
        "ColoCode": "CDG",
        "ColoID": 533,
        "Location": "AWS VM",
        "LocationID": "a26c188f-10c2-4333-8ed4-c823fafa06f6",
        "QueryNameReversed": "internal.compute.eu-west-3.ip-111-30-40-252",
        "QuerySize": 72,
        "QueryType": "1",
        "ResolverDecision": "allowedOnNoPolicyMatch",
        "TimeZoneInferredMethod": "noScheduleConfigured"
    },
    "related": {
        "ip": [
            "104.18.4.35",
            "104.18.5.35",
            "12.122.186.81",
            "172.12.12.1"
        ],
        "hosts": [
            "ip-111-30-40-252.eu-west-3.compute.internal"
        ]
    }
}

{
    "message": "{\"ApplicationID\":0,\"ColoCode\":\"CDG\",\"ColoID\":534,\"Datetime\":\"2023-05-02T16:24:19Z\",\"DeviceID\":\"b72ac397-e5c3-913e-11ed-03face9f2b6b\",\"DeviceName\":\"DESKTOP-ABCDEF\",\"DstIP\":\"162.159.36.1\",\"DstPort\":443,\"Email\":\"john.doe@test.com\",\"Location\":\"loc-01\",\"LocationID\":\"a26c158f-10c2-4223-8ed4-c845fafa06f6\",\"MatchedCategoryIDs\":[],\"MatchedCategoryNames\":[],\"Policy\":\"\",\"PolicyID\":\"\",\"Protocol\":\"https\",\"QueryCategoryIDs\":[21,80],\"QueryCategoryNames\":[\"Security threats\",\"Command and Control & Botnet\"],\"QueryName\":\"commandandcontrolandbotnet.testcategory.com\",\"QueryNameReversed\":\"com.testcategory.commandandcontrolandbotnet\",\"QuerySize\":72,\"QueryType\":65,\"QueryTypeName\":\"HTTPS\",\"RCode\":0,\"RData\":[{\"type\":\"65\",\"data\":\"GmNvbW1hbmRhbmRjb250cm9sYW5kYm90bmV0DHRlc3RjYXRlZ29yeQNjb20AAEEAAQAAADwAOgABAAABAAMCaDIABAAIaBIEI2gSBSMABgAgJgZHAAAAAAAAAAAAaBIEIyYGRwAAAAAAAAAAAGgSBSM=\"}],\"ResolvedIPs\":[],\"ResolverDecision\":\"allowedOnNoPolicyMatch\",\"SrcIP\":\"15.188.186.81\",\"SrcPort\":0,\"TimeZone\":\"\",\"TimeZoneInferredMethod\":\"noScheduleConfigured\",\"UserID\":\"2c46cdd9-92e3-5e5f-b3cf-67965d7c33e3\"}",
    "event": {
        "category": [
            "network"
        ],
        "dataset": "gateway_dns",
        "kind": "event",
        "type": [
            "info"
        ]
    },
    "destination": {
        "ip": "162.159.36.1",
        "port": 443,
        "address": "162.159.36.1"
    },
    "@timestamp": "2023-05-02T16:24:19Z",
    "device": {
        "id": "b72ac397-e5c3-913e-11ed-03face9f2b6b"
    },
    "dns": {
        "question": {
            "name": "commandandcontrolandbotnet.testcategory.com",
            "type": "HTTPS",
            "top_level_domain": "com",
            "subdomain": "commandandcontrolandbotnet",
            "registered_domain": "testcategory.com"
        },
        "resolved_ip": [],
        "response_code": "NoError"
    },
    "host": {
        "hostname": "DESKTOP-ABCDEF",
        "name": "DESKTOP-ABCDEF"
    },
    "network": {
        "protocol": "dns",
        "transport": "https"
    },
    "observer": {
        "type": "dns",
        "vendor": "Cloudflare"
    },
    "source": {
        "port": 0,
        "ip": "15.188.186.81",
        "address": "15.188.186.81"
    },
    "user": {
        "email": "john.doe@test.com",
        "id": "2c46cdd9-92e3-5e5f-b3cf-67965d7c33e3"
    },
    "cloudflare": {
        "ApplicationID": 0,
        "ColoCode": "CDG",
        "ColoID": 534,
        "Location": "loc-01",
        "LocationID": "a26c158f-10c2-4223-8ed4-c845fafa06f6",
        "QueryCategoryIDs": [
            21,
            80
        ],
        "QueryCategoryNames": [
            "Security threats",
            "Command and Control & Botnet"
        ],
        "QueryNameReversed": "com.testcategory.commandandcontrolandbotnet",
        "QuerySize": 72,
        "QueryType": "65",
        "RData": [
            {
                "type": "65",
                "data": "GmNvbW1hbmRhbmRjb250cm9sYW5kYm90bmV0DHRlc3RjYXRlZ29yeQNjb20AAEEAAQAAADwAOgABAAABAAMCaDIABAAIaBIEI2gSBSMABgAgJgZHAAAAAAAAAAAAaBIEIyYGRwAAAAAAAAAAAGgSBSM="
            }
        ],
        "ResolverDecision": "allowedOnNoPolicyMatch",
        "TimeZoneInferredMethod": "noScheduleConfigured"
    },
    "related": {
        "hosts": [
            "DESKTOP-ABCDEF",
            "commandandcontrolandbotnet.testcategory.com"
        ],
        "ip": [
            "15.188.186.81",
            "162.159.36.1"
        ]
    }
}

Extracted Fields

The following table lists the fields that are extracted, normalized under the ECS format, analyzed and indexed by the parser. It should be noted that infered fields are not listed.

Name	Type	Description
`@timestamp`	`date`	Date/time when the event originated.
`cloudflare.ApplicationID`	`number`	ID of the application the domain belongs to (for example, 1, 2). Set to 0 when no ApplicationID is matched.
`cloudflare.ColoCode`	`keyword`	The name of the colo that received the DNS query (for example, ‘SJC’, ‘MIA’, ‘IAD’).
`cloudflare.ColoID`	`number`	The ID of the colo that received the DNS query (for example, 46, 72, 397).
`cloudflare.Location`	`keyword`	Name of the location the DNS request is coming from. Location is created by the customer (for example, ‘Office NYC’).
`cloudflare.LocationID`	`keyword`	UUID of the location the DNS request is coming from. Location is created by the customer (for example, ‘7bdc7a9c-81d3-4816-8e56-000000000000’).
`cloudflare.MatchedCategoryIDs`	`array`	ID or IDs of category that the domain was matched with the policy (for example, [7,12,28,122,129,163]).
`cloudflare.MatchedCategoryNames`	`array`	Name or names of category that the domain was matched with the policy (for example, [‘Photography’, ‘Weather’]).
`cloudflare.Policy`	`keyword`	ID of the policy/rule that was applied (if any).
`cloudflare.QueryCategoryIDs`	`array`	ID or IDs of category that the domain belongs to (for example, [7,12,28,122,129,163]).
`cloudflare.QueryCategoryNames`	`array`	Name or names of category that the domain belongs to (for example, [‘Photography’, ‘Weather’]).
`cloudflare.QueryNameReversed`	`keyword`	Query name in reverse (for example, ‘com.example’).
`cloudflare.QuerySize`	`number`	The size of the DNS request in bytes (for example, 151).
`cloudflare.QueryType`	`keyword`	The type of DNS query (for example, ‘1’, ‘28’, ‘15’, or ‘16’).
`cloudflare.RData`	`array`	The rdata objects (for example, {“type”:“5”,“data”:“dns-packet-placeholder…”}).
`cloudflare.ResolverDecision`	`keyword`	Result of the DNS query (for example, ‘overrideForSafeSearch’).
`cloudflare.TimeZone`	`keyword`	Time zone used to calculate the current time, if a matched rule was scheduled with it.
`cloudflare.TimeZoneInferredMethod`	`keyword`	Method used to pick the time zone for the schedule (from rule/ from user ip/ from local time).
`destination.ip`	`ip`	IP address of the destination.
`destination.port`	`long`	Port of the destination.
`dns.question.name`	`keyword`	The name being queried.
`dns.question.type`	`keyword`	The type of record being queried.
`dns.resolved_ip`	`ip`	Array containing all IPs seen in answers.data
`event.category`	`keyword`	Event category. The second categorization field in the hierarchy.
`event.dataset`	`keyword`	Name of the dataset.
`event.kind`	`keyword`	The kind of the event. The highest categorization field in the hierarchy.
`event.type`	`keyword`	Event type. The third categorization field in the hierarchy.
`host.hostname`	`keyword`	Hostname of the host.
`network.protocol`	`keyword`	Application protocol name.
`network.transport`	`keyword`	Protocol Name corresponding to the field `iana_number`.
`observer.type`	`keyword`	The type of the observer the data is coming from.
`observer.vendor`	`keyword`	Vendor name of the observer.
`source.ip`	`ip`	IP address of the source.
`source.port`	`long`	Port of the source.
`user.email`	`keyword`	User email address.
`user.id`	`keyword`	Unique identifier of the user.

Configuration

Create the intake on SEKOIA.IO

Go to the intake page and create a new intake from the format Cloudflare.

Configure events forwarding on Cloudflare

Retrieve necessary information

First, you will have to retrieve configuration information. Connect to Cloudflare Console to collect the following :

Cloudflare API Token
- Go to My Profile, then on the left panel, click on API Tokens.
- Click on the Create Token button and select the Create Custom Token entry.
- Give a name to your token and set the following permissions:
Scope Group Level

Account Account Analytics Read

Account Logs Read

Account Logs Edit

Zone Logs Read

Zone Logs Edit
- If you want zerotrust logs you should also add:
Scope Group Level

Account Zero Trust Read

see the Cloudflare documentation
Cloudflare Zone ID :
- This information is specific to a Website.
- On the left panel, click on Websites and select the Website you want.
- On the right panel, there is an API section where you can retrieve the Zone ID.

Create a Logpush job

Configure a Logpush job with the following destination:

https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>

To do so, you can manage Logpush with cURL:

$ curl -X POST 'https://api.cloudflare.com/client/v4/accounts/<CLOUDFLARE_ACCOUNT_ID>/logpush/jobs' \
-H 'Authorization: Bearer <CLOUDFLARE_API_TOKEN>' \
-H "Content-Type: application/json" \
-d '{
    "dataset": "gateway_dns",    
    "enabled": true,     
    "max_upload_bytes": 5000000,     
    "max_upload_records": 1000,
    "logpull_options":"fields=ApplicationID,ColoCode,ColoID,Datetime,DeviceID,DeviceName,DstIP,DstPort,Email,Location,LocationID,MatchedCategoryIDs,MatchedCategoryNames,Policy,PolicyID,Protocol,QueryCategoryIDs,QueryCategoryNames,QueryName,QueryNameReversed,QuerySize,QueryType,QueryTypeName,RCode,RData,ResolvedIPs,ResolverDecision,SrcIP,SrcPort,TimeZone,TimeZoneInferredMethod,UserID&timestamps=rfc3339",
    "destination_conf": "https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>"
    }' # (1)

will return

{
  "errors": [],
  "messages": [],
  "result": {
    "id": "<ID>",
    "dataset": "gateway_dns",
    "frequency":"high",
    "kind":"", 
    "max_upload_bytes": 5000000,     
    "max_upload_records": 1000, 
    "enabled": true,
    "name": "<DOMAIN_NAME>",
    "logpull_options": "fields=<LIST_OF_FIELDS>",
    "destination_conf": "https://intake.sekoia.io/plain/batch?header_X-SEKOIAIO-INTAKE-KEY=<YOUR_INTAKE_KEY>",
    "last_complete": null,
    "last_error": null,
    "error_message": null,
    "time_created":"<TIMESTAMP>"
  },
  "success": true
}

Important

Replace :

<YOUR_INTAKE_KEY> with the Intake key you generated in the Create the intake on SEKOIA.IO step.
<CLOUDFLARE_ACCOUNT_ID> with the ACCOUNT_ID found on the overview page
<CLOUDFLARE_API_TOKEN> with the API Token you generated

Useful Cloudflare API endpoints

On their documentation, Cloudflare provides a list API endpoints you can use. Find below some useful endpoints:

https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/logpush/jobs/<JOB_ID> to verify the job you previously created is correct (you need to specify the JOB_ID)
https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/logpush/datasets/<DATASET>/jobs to get all the jobs for a specific dataset (dns_log, firewalls_events or http_requests in our case)
https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/logpush/jobs/<JOB_ID> to update a job if you noticed a mistake after the creation of the job (wrong fields, wrong SEKOIA API Key...)

Scope	Group	Level
Account	Account Analytics	Read
Account	Logs	Read
Account	Logs	Edit
Zone	Logs	Read
Zone	Logs	Edit